How do I search each of these keywords from a single text field?

Can't speak to UniBasic, but in VB.Net I'd take the whole string and SPLIT it on the spaces (between words), putting each section/word in an array so each word could be used individually.

can you give me an example?

Maybe some ideas here?:

http://www.emacswiki.org/emacs/UniBasic.el

Example of PaulMacD's answer, making a change to split on "," instead of spaces
given:
form field=txtSearch
instructions to user are to comma sperate search words (in case one word has a space in it)

dim keywords()
keywords=split(txtsearch,",")
ado.open "Select * from Mytable where myfield like('%"+join(keywords,"%'), or myfield like ('%")+"%')",adodc

results, if the txtsearch ="value1,value2" you be running a query of:
Select * from Mytable where myfield like('%value1%') or myfield like('%value2%')

split is not available as a command in UniBasic. I haven't found anything comparable.

Is there a another way to do this using Basic Programming?

Is there a "substring" equivilent?  That is, can you search for commas, then grab the portion of the string between the last comma and the next one?  

This could be done by looping through the string from the beginning, looing for a comma.  When you find (the first) one, grab the portion of the string from the beginning to the comma, store it in an array, then start searching for the next comma from one character after the comma you just found.  If you reach the end of the string, you have your last term.

Yes, there is a substring command. Can you give me an example that would look for spaces and parse out the words for searching?

Thanks